The present invention relates to milk carton blanks and, more particularly, to a milk carton blank formed from a sheet of laminated composite material having a central layer of paperboard material and having a single layer of plastic material adhesively secured to each surface of the paper material which is formable into a liquid tight carton having a right regular parallelepiped shape which may be provided with a pouring spout formed entirely from the unitary milk carton blank.
Over the past several decades, a number of containers have been designed for use in storing consumable liquids such as milk and the like.
Stetler, U.S. Pat. No. 3,985,287 discloses a one-piece blank which is formable into a carton having a rectangular cross-section. The carton is adapted for use as a half gallon milk carton and the sheet material used for the carton blank is 24 point paperboard coated with polyethylene on both sides. The sealing of the carton is effected by pressing adjacent portions together and applying heat to melt the polyethylene.
The blank is provided with a plurality of crease/fold lines which allow it to be folded into a rectangular box-like configuration. Crease lines form four side panels. Two side panels of lesser width each are provided with "half flaps" at their ends. When the carton is folded, each half flap extends slightly more than half way across the end of the carton, overlapping enough to enable formation of a seal. A plurality of the blanks can be internested for cutting from a single sheet of material. For this purpose, the width of each of the greater width side panels is made equal to the sum of the width of one of the lesser width side panels plus twice the combined width of the pair of sealing flaps at the sides of one of the end panels.
Steinke et al, U.S. Pat. No. 4,308,956, discloses a resealable container which may have a square or rectangular three-dimensional configuration formed from a generally rectangular carton blank. The carton blank may be constructed from cardboard, pasteboard, kraft, newsback board, solid bleached sulfate, or certain polymeric materials capable of being scored, folded, and die-cut, such as polyethylene.
The blank from which the carton is cut is subdivided into a plurality of rectangular panel portion. The top panel portions having specially adapted cutout portions therein which, when folded together, create a resealable flap. A hinge flap portion is adapted to open and close the container with a diecut portion secured to the hinge flap. The carton is especially adapted for dispensing particulate or powdered material.
Carlsson, U.S. Pat. No. 4,113,103, discloses an opening arrangement for packing containers and shows a packing container having a parallelepiped (rectangular box) shape which is made of a laminated carton forming material comprising a carrier layer of paper provided on both sides with layers of plastic material which are impervious to liquid.
The opening arrangement is positioned partially on the carton top panel and partially on a lateral side panel of the carton. The opening arrangement comprises a lug which is an integral part of the material of the packing container but which is delimited by a weakening or perforated line which extends onto portions of both the top and side panels. To prevent the contents of the package from leaking out through the perforation holes and weakening line, a cover layer is provided underneath the openable part. The cover layer consists of a strip of plastic film and is joined to the inside of the laminated packaging material (the side facing towards the inside of the package) in a continuous sealing zone which extends between the edge line of the cover layer and the perforation line. The opening arrangement further comprises a flexible material strip situated between the cover layer and the packaging laminate. The material strip is positioned within the sealing zone in which cover layer is joined to the packing laminate. The main part of the flexible material strip is situated underneath and extends parallel with the top end surface while a front end of material strip extends over the edge dividing top and side panels. The material strip is manufactured from a flexible resilient and relatively stiff plastic material which after deformation or folding directly reassumes its original form. The outer edge of strip is folded at intersection line prior to the opening of lug. However, after the lug is opened, the strip extends outward to provide a pouring edge. A pouring opening is provided in the flexible strip and an upper portion of cover layer directly below the opening is adhered to the lower surface of lug whereby it is torn free from layer when the lug is opened, allowing passage of liquid through the opening.
Christensson, U.S. Pat. No. 3,613,986, discloses a liquid container having a cardboard outer container formed from a carton blank and a inner plastic liner. The carton has side panel portions each having two end flaps which are separated by cutouts and which are inwardly foldable to define a rectangular box configuration. On an inner most top flap is formed a pouring opening comprising a hole through the cardboard and the plastic liner and a pair of additional plastic layers, one on the inside of the opening and one on the outside of the opening. The additional pair of plastic layers are welded to each other at the opening. A grip tongue is provided for tearing away parts of the two additional plastic layers.
Meyer-Jagenberg, U.S. Pat. No. 3,127,082, discloses a generally rectangular container of paper cardboard or the like consisting of a tubular body, the ends of which are provided with closures. One of the closures is a roof shaped bellows fold closure. In the region of one of the inwardly folded gable portions of such closure, a pouring aperture 2 is provided. Pouring aperture may be formed by punching end portion 1.
Farfaglia et al, U.S. Pat. No. 3,825,408 discloses a hot air heater for heat sealing a thermoplastic coated, paperboard milk carton.
Frydendal, U.S. Pat. No. 4,300,969 discloses a laminate for use in cartons for milk, etc. consisting of a cardboard web, a layer of heat sealable thermoplastic material such as polyethylene on the side of the laminate forming the outside of the cartons and three layers of plastic material on the other side, the inner most layer of which may be colored.
Rausing et al, U.S. Pat. No. 3,347,444 discloses a generally rectangular container having a pouring spout formed by tearing out a portion of an end wall flap.
A problem inherent in prior art configurations has been that a carton design capable of providing an adequate pouring spout has either required an elaborate fabrication procedure or must be provided in a shape which does not lend itself to easy, convenient and space-saving storage and packaging. Another problem with prior art containers has been that the milk carton blank configurations have required elaborate cutting, folding, and sealing operations to provide a liquid tight container.